Bridge

A structure that spans a body of water, a valley, or a road and affords passage for pedestrians, or vehicles of all kinds, or any combination thereof.

Introduction

A bridge is a means by which a road, railway or other service is carried over an obstacle such as a river, valley, other road or railway line, either with no intermediate support or with only a limited number of supports at convenient locations. Bridges range in size from very modest short spans over, say, a small river to the extreme examples of suspension bridges crossing wide estuaries. Appearance is naturally less crucial for the smaller bridges, but in all cases the designer will consider the appearance of the basic elements which make up his bridge, the superstructure and the substructure, and choose proportions which are appropriate to the particular circumstances considered. The use of steel often helps the designer to select proportions that are aesthetically pleasing.

Basic Features of Bridges

External Links

• AASHTO Photos of US Bridges, State by State
• Wikipedia Index of Bridge Types and Bridge Taxonomy
• Structurae International Database and Gallery of Structures
• The Basic Bridge Types Girder, Arch, Truss, Cable-Stayed, Rigid Frame, Supension